There is considerable interest in methods for detecting airborne and waterborne chemical contaminants, among others, that are present in small concentrations in a carrier fluid. In one class of sensors useful for such purposes, selective binding events take place between the analyte and receptor molecules in the sensor, resulting in a measurable change in the physical properties of the receptor. For example, in a method for detecting airborne molecules of explosive compounds such as the nitroaromatics 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) as well as other nitro compounds such as pentaerythritol tetranitrate (PETN), binding of the analyte molecules to fluorescent polymers causes detectable fluorescence quenching.
Despite this and other similar technologies, however, there remains a need for improved chemical sensors with greater sensitivity, selectivity, and reliability. In particular, there is a need for an integrated chemical sensor which combines excellent sensitivity and selectivity with a small form factor that ideally could be integrated into portable devices such as smart phones.